A power converter is widely applied to fields such as variable frequency drive, wind power generation, and photovoltaic power generation. In the power converter, a bus capacitor provides main functions such as high-frequency filtering, maintaining bus voltage stability, and energy support, but the cost of the bus capacitor is high and occupies a large proportion in the cost structure of the power converter. Therefore, reducing bus capacitor usage becomes an important way of reducing the cost of the power converter.
At present, the prior art provides a power converter in modular design. As shown in FIG. 1, such a power converter is formed by directly connecting power modules 101 in parallel using copper bars 102. However, large parasitic inductance exists between direct current bus capacitors of different power modules. As shown in FIG. 2, FIG. 2 is a schematic diagram of a circuit principle of two inverting modules connected in parallel. In FIG. 2, a power converter includes an inverting module 1 and an inverting module 2, where the inverting module 1 includes an insulated gate bipolar transistor (IGBT) module A1, an IGBT module B1 and an IGBT module C1, the inverting module 2 includes an IGBT module A2, an IGBT module B2 and an IGBT module C2, and the IGBT module A1 and the IGBT module A2 are connected in parallel. Here the IGBT modules are IGBT inverting modules, and equivalent series inductance (ESL) exists in a current loop 2 between the IGBT module A1 and the IGBT module A2, where the parasitic inductance ESL is parasitic inductance existing among direct current bus capacitors of different power modules. Therefore, the problem to be solved currently is how to reduce the parasitic inductance.